/* ==========================================================================
   Jiangsu Haida Metal Materials Co., Ltd. - style.css
   Mobile-first, breakpoints: 768px / 1024px. Palette: steel blue + dark grey.
   ========================================================================== */
:root{
  --primary:#1a3a5c;
  --primary-dark:#12283f;
  --primary-light:#2e5a85;
  --grey-dark:#3a4149;
  --grey-mid:#6b7480;
  --grey-light:#f4f6f8;
  --line:#dfe4ea;
  --white:#ffffff;
  --shadow:0 2px 10px rgba(18,40,63,.10);
  --shadow-lg:0 8px 24px rgba(18,40,63,.16);
  --radius:6px;
  --container:1320px;
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--grey-dark);
  background:var(--white);
  line-height:1.65;
  font-size:16px;
  -webkit-text-size-adjust:100%;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--primary-light);text-decoration:none}
a:hover{color:var(--primary)}
h1,h2,h3,h4{color:var(--primary);line-height:1.25;margin:0 0 .6em}
h1{font-size:1.9rem}
h2{font-size:1.5rem}
h3{font-size:1.15rem}
p{margin:0 0 1em}
ul{padding-left:1.2em}
.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 20px}
.section{padding:56px 0}
.section-alt{background:var(--grey-light)}
.section-head{max-width:760px;margin:0 auto 36px;text-align:center}
.section-head p{color:var(--grey-mid)}
.skip-link{position:absolute;left:-999px;top:0;background:var(--primary);color:#fff;padding:8px 16px;z-index:200}
.skip-link:focus{left:8px;top:8px;color:#fff}

/* ---------- Buttons ---------- */
.btn{
  display:inline-block;background:var(--primary);color:#fff;
  padding:12px 28px;border-radius:var(--radius);font-weight:600;
  border:2px solid var(--primary);transition:background .25s,border-color .25s;
  cursor:pointer;font-size:1rem;text-align:center;
}
.btn:hover{background:var(--primary-dark);border-color:var(--primary-dark);color:#fff}
.btn-outline{background:transparent;color:#fff;border-color:#fff}
.btn-outline:hover{background:#fff;color:var(--primary);border-color:#fff}
.btn-sm{padding:9px 18px;font-size:.92rem}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:100;background:var(--white);
  border-bottom:1px solid var(--line);transition:box-shadow .25s;
}
.site-header.scrolled{box-shadow:var(--shadow)}
.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:72px;gap:16px}
.brand img{height:44px;width:auto}
.nav-toggle{
  display:inline-flex;flex-direction:column;justify-content:center;gap:5px;
  width:44px;height:44px;background:none;border:0;cursor:pointer;padding:8px;
}
.nav-toggle span{display:block;height:3px;width:100%;background:var(--primary);border-radius:2px;transition:transform .25s,opacity .25s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(8px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-8px) rotate(-45deg)}

.site-nav{
  position:fixed;top:0;right:-290px;width:280px;height:100vh;
  background:var(--white);box-shadow:var(--shadow-lg);
  transition:right .3s ease;z-index:99;overflow-y:auto;padding:88px 20px 24px;
}
.site-nav.open{right:0}
.menu{list-style:none;margin:0;padding:0}
.menu>li{border-bottom:1px solid var(--line);position:relative}
.menu>li>a{display:block;padding:14px 4px;color:var(--grey-dark);font-weight:600}
.menu>li>a:hover{color:var(--primary)}
.dropdown-toggle{
  position:absolute;top:6px;right:0;width:40px;height:40px;border:0;background:none;cursor:pointer;
}
.dropdown-toggle::after{
  content:"";display:block;width:8px;height:8px;border-right:2px solid var(--grey-mid);
  border-bottom:2px solid var(--grey-mid);transform:rotate(45deg);margin:0 auto;transition:transform .2s;
}
.dropdown-toggle[aria-expanded="true"]::after{transform:rotate(-135deg)}
.dropdown{list-style:none;margin:0;padding:0 0 8px 12px;display:none}
.dropdown.open{display:block}
.dropdown a{display:block;padding:9px 4px;font-size:.95rem;color:var(--grey-mid)}
.dropdown a:hover{color:var(--primary)}
.menu .divider{border-top:1px dashed var(--line);margin-top:6px;padding-top:6px}
.btn-nav{margin:18px 4px 0;display:inline-block}
.nav-backdrop{position:fixed;inset:0;background:rgba(18,40,63,.45);opacity:0;visibility:hidden;transition:opacity .3s;z-index:98}
.nav-backdrop.show{opacity:1;visibility:visible}

/* ---------- Hero (home) ---------- */
.hero{
  position:relative;color:#fff;
  background:
    linear-gradient(100deg,rgba(18,40,63,.92) 0%,rgba(26,58,92,.82) 45%,rgba(26,58,92,.55) 100%),
    url("../images/hero-coils.jpg") center/cover no-repeat;
  padding:88px 0;
}
.hero h1{color:#fff;font-size:2.1rem;max-width:720px}
.hero p{max-width:640px;font-size:1.05rem;color:#dbe5ef}
.hero-actions{margin-top:28px;display:flex;gap:14px;flex-wrap:wrap}
.hero-badges{margin-top:34px;display:flex;gap:10px 22px;flex-wrap:wrap;list-style:none;padding:0}
.hero-badges li{font-size:.92rem;color:#c9d6e2}
.hero-badges li::before{content:"\2713";color:#7fc06e;margin-right:8px;font-weight:700}
.hero-inner{display:grid;gap:36px;align-items:center}
.hero-media{
  max-width:500px;margin:0 auto;border-radius:8px;overflow:hidden;
  border:1px solid rgba(255,255,255,.30);background:rgba(255,255,255,.10);
  box-shadow:0 22px 48px rgba(4,14,26,.55);
}
.hero-media img{width:100%;height:auto;display:block}

/* ---------- Page hero (subpages) ---------- */
.page-hero{
  background:linear-gradient(100deg,var(--primary-dark),var(--primary-light));
  color:#fff;padding:52px 0;
}
.page-hero h1{color:#fff;margin-bottom:.25em}
.page-hero p{color:#c9d6e2;max-width:720px;margin:0}
.breadcrumb{list-style:none;display:flex;flex-wrap:wrap;gap:6px;padding:0;margin:14px 0 0;font-size:.88rem;color:#aebfd0}
.breadcrumb li+li::before{content:"/";margin-right:6px;color:#7d92a8}
.breadcrumb a{color:#dce6f0}
.breadcrumb [aria-current="page"]{color:#fff}

/* ---------- Grids & cards ---------- */
.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:1fr}
.grid-3{grid-template-columns:1fr}
.grid-4{grid-template-columns:1fr 1fr}
.card{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);overflow:hidden;transition:transform .25s,box-shadow .25s;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.card-media{aspect-ratio:4/3;overflow:hidden;background:#e9edf1}
.card-media img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.card:hover .card-media img{transform:scale(1.05)}
.card-body{padding:20px}
.card-body p{color:var(--grey-mid);font-size:.95rem}
.text-link{font-weight:600}
.card-flat{padding:26px}
.card-flat h3{margin-bottom:.4em}
.card-flat p{font-size:.95rem;color:var(--grey-mid);margin:0}

/* product detail layout */
.product-layout{display:grid;gap:32px}
.product-media{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#e9edf1}
.product-media img{width:100%;object-fit:cover}
.highlight-box{
  background:#eef4fa;border-left:4px solid var(--primary);border-radius:0 var(--radius) var(--radius) 0;
  padding:16px 20px;margin:20px 0;
}
.highlight-box p{margin:0}

/* spec table */
.table-wrap{overflow-x:auto;margin:20px 0}
.spec-table{width:100%;border-collapse:collapse;min-width:520px;font-size:.95rem}
.spec-table th,.spec-table td{border:1px solid var(--line);padding:10px 14px;text-align:left;vertical-align:top}
.spec-table thead th{background:var(--primary);color:#fff;border-color:var(--primary)}
.spec-table tbody tr:nth-child(even){background:var(--grey-light)}
.spec-table td:first-child{font-weight:600;color:var(--primary);width:32%}

/* why choose us */
.why-card{text-align:center;padding:30px 22px}
.why-icon{width:58px;height:58px;margin:0 auto 16px;color:var(--primary)}
.why-icon svg{width:100%;height:100%}
.why-card h3{font-size:1.05rem}
.why-card p{font-size:.92rem;margin:0}

/* applications */
.app-card .card-body{padding:14px 18px}
.app-card h3{margin:0;font-size:1rem}

/* CTA band */
.cta-band{background:linear-gradient(100deg,var(--primary-dark),var(--primary));color:#fff;padding:52px 0;text-align:center}
.cta-band h2{color:#fff}
.cta-band p{color:#c9d6e2;max-width:640px;margin:0 auto 24px}

/* ---------- FAQ accordion ---------- */
.faq-item{border:1px solid var(--line);border-radius:var(--radius);margin-bottom:14px;background:var(--white);overflow:hidden}
.faq-q{
  width:100%;display:flex;justify-content:space-between;align-items:center;gap:16px;
  background:none;border:0;padding:18px 20px;text-align:left;cursor:pointer;
  font-size:1.02rem;font-weight:600;color:var(--primary);font-family:inherit;
}
.faq-q .faq-icon{flex:none;width:22px;height:22px;position:relative}
.faq-q .faq-icon::before,.faq-q .faq-icon::after{
  content:"";position:absolute;background:var(--primary);border-radius:2px;transition:transform .25s;
}
.faq-q .faq-icon::before{width:16px;height:3px;top:9.5px;left:3px}
.faq-q .faq-icon::after{width:3px;height:16px;top:3px;left:9.5px}
.faq-item.open .faq-q .faq-icon::after{transform:scaleY(0)}
.faq-a{max-height:0;overflow:hidden;transition:max-height .3s ease}
.faq-a-inner{padding:0 20px 20px;color:var(--grey-mid)}
.faq-a-inner p:last-child{margin-bottom:0}

/* ---------- Blog ---------- */
.post-meta{font-size:.88rem;color:var(--grey-mid);margin-bottom:8px}
.article-body{max-width:820px}
.article-body h2{margin-top:1.6em}
.article-body img{border-radius:var(--radius);margin:8px 0 20px}

/* ---------- Forms ---------- */
.contact-layout{display:grid;gap:36px}
.form-field{margin-bottom:18px}
.form-field label{display:block;font-weight:600;margin-bottom:6px;color:var(--primary)}
.form-field input,.form-field textarea{
  width:100%;padding:11px 14px;border:1px solid var(--line);border-radius:var(--radius);
  font:inherit;color:var(--grey-dark);background:var(--white);
}
.form-field input:focus,.form-field textarea:focus{outline:2px solid var(--primary-light);border-color:var(--primary-light)}
.form-field .error-msg{display:none;color:#c0392b;font-size:.85rem;margin-top:5px}
.form-field.invalid input,.form-field.invalid textarea{border-color:#c0392b}
.form-field.invalid .error-msg{display:block}
.form-status{margin-top:14px;font-weight:600;color:var(--primary);display:none}
.contact-info-card{background:var(--grey-light);border-radius:var(--radius);padding:26px}
.contact-info-card h2{margin-bottom:1em}
.contact-list{list-style:none;padding:0;margin:0}
.contact-list li{display:flex;gap:12px;margin-bottom:16px}
.contact-list strong{color:var(--primary);display:block;font-size:.9rem}
.contact-list a{word-break:break-all}

/* ---------- Footer ---------- */
.site-footer{background:var(--primary-dark);color:#b9c7d4;margin-top:0}
.footer-grid{display:grid;gap:32px;padding:52px 20px 36px}
.site-footer h2{color:#fff;font-size:1.05rem;margin-bottom:14px}
.site-footer p{font-size:.93rem}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-bottom:9px}
.site-footer a{color:#b9c7d4;font-size:.93rem}
.site-footer a:hover{color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding:18px 20px;font-size:.86rem;display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap}

/* ---------- Back to top ---------- */
.to-top{
  position:fixed;right:18px;bottom:18px;width:44px;height:44px;border-radius:50%;
  background:var(--primary);color:#fff;border:0;cursor:pointer;opacity:0;visibility:hidden;
  transition:opacity .25s,visibility .25s;z-index:90;font-size:1.1rem;
}
.to-top.show{opacity:1;visibility:visible}

/* ==========================================================================
   Tablet >=768px
   ========================================================================== */
@media (min-width:768px){
  h1{font-size:2.3rem}
  h2{font-size:1.75rem}
  .hero{padding:110px 0}
  .hero-inner{grid-template-columns:1.1fr .9fr}
  .hero-media{max-width:460px;margin:0 auto}
  .grid-2{grid-template-columns:1fr 1fr}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .product-layout{grid-template-columns:1fr 1fr;align-items:start}
  .contact-layout{grid-template-columns:1.2fr .8fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .section{padding:72px 0}
}

/* ==========================================================================
   Desktop >=1024px
   ========================================================================== */
@media (min-width:1024px){
  .nav-toggle,.nav-backdrop,.dropdown-toggle{display:none}
  .site-nav{
    position:static;width:auto;height:auto;box-shadow:none;overflow:visible;
    padding:0;display:flex;align-items:center;gap:8px;
  }
  .menu{display:flex;align-items:center;gap:6px}
  .menu>li{border-bottom:0}
  .menu>li>a{padding:10px 14px}
  .menu>li>a:hover{background:var(--grey-light);border-radius:4px}
  .dropdown{
    display:block;position:absolute;top:100%;left:0;min-width:280px;background:var(--white);
    box-shadow:var(--shadow-lg);border-radius:0 0 var(--radius) var(--radius);
    padding:8px 0;opacity:0;visibility:hidden;transform:translateY(8px);
    transition:opacity .2s,transform .2s,visibility .2s;z-index:50;border-top:3px solid var(--primary);
  }
  .has-dropdown:hover .dropdown,.has-dropdown:focus-within .dropdown{opacity:1;visibility:visible;transform:translateY(0)}
  .dropdown a{padding:10px 20px;color:var(--grey-dark)}
  .dropdown a:hover{background:var(--grey-light);color:var(--primary)}
  .menu .divider{border-top:1px dashed var(--line);margin:6px 12px;padding:0}
  .grid-3{grid-template-columns:repeat(3,1fr)}
  .grid-4{grid-template-columns:repeat(4,1fr)}
  .footer-grid{grid-template-columns:1.3fr 1fr 1fr 1.2fr}
  .hero h1{font-size:2.7rem}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{transition:none!important;animation:none!important}
  html{scroll-behavior:auto}
}